John B. Waldman

Relationship Between Provider Volume and Mortality for Carotid Endarterectomies in New York State

BACKGROUND AND PURPOSE The objective of this study was to assess the relationship between each of 2 provider volume measures for carotid endarterectomies (CEs) (annual hospital volume and annual surgeon volume) and in-hospital mortality. New Yorks Statewide Planning and Research (SPARCS) administrative database was used to identify all 28 207 patients for whom carotid endarterectomy was the principal procedure performed in New York State hospitals between January 1, 1990, and December 31, 1995. METHODS A statistical model was developed to predict in-hospital mortality using age, admission status, and several conditions found to be associated with higher-than-average mortality. This model was then used to calculate risk-adjusted mortality rates for various intersections of hospital and surgeon volume ranges. RESULTS Risk-adjusted in-hospital mortality ranged from 1.96% (95% confidence interval, 1.47 to 2.57) for patients having surgeons with annual CE volumes of <5 in hospitals with annual CE volumes of </=100 to 0.94% (95% confidence interval, 0.73 to 1.19) for patients having surgeons with annual volumes of >/=5 in hospitals with annual CE volumes of >100. These 2 rates were statistically different. CONCLUSIONS We conclude that the in-hospital mortality rates for carotid endarterectomies performed by surgeons with extremely low annual volumes (<5) and for hospitals with low volumes (</=100) are significantly higher than the in-hospital rates of higher-volume surgeons and hospitals, even after taking preprocedural patient severity of illness into account.

Decompressive craniectomy and postoperative complication management in infants and toddlers with severe traumatic brain injuries.

OBJECT Infants with severe traumatic brain injury represent a therapeutic challenge. The internal absence of open space within the infant cranial vault makes volume increases poorly tolerated. This report presents 7 cases of decompressive craniectomy in infants with cerebral edema. METHODS The authors reviewed the medical charts of infants with brain injuries who presented to Albany Medical Center Hospital between January 2004 and July 2007. Variables that were examined included patient age, physical examination results at admission, positive imaging findings, surgery performed, complications, requirement of permanent CSF diversion, and physical examination results at discharge and outpatient follow-up using the Kings Outcome Scale for Childhood Head Injury. Seven infants met the inclusion criteria for the study. Six infants experienced nonaccidental trauma, and 1 had a large infarction of the middle cerebral artery territory secondary to a carotid dissection. At admission, all patients were minimally responsive, 4 had equal and minimally reactive pupils, 3 had anisocoria with the enlarged pupil on the same side as the brain lesion, and all had right-sided hemiparesis. Six patients received a left hemicraniectomy, whereas 1 received a left frontal craniectomy. In all cases, bone was cultured and stored at the bone bank. RESULTS Postoperatively, 3 patients who developed draining CSF fistulas needed insertions of external ventricular drains, with incisions oversewn using nylon sutures and a liquid bonding agent. After prolonged CSF drainage and wound care, these patients all developed epidural and subdural empyemas necessitating surgical drainage and debridement. Methicillin-resistant Staphylococcus aureus was found in 2 patients and Enterococcus in the third. All patients developed hydrocephalus necessitating the insertion of a ventriculoperitoneal shunt, and all had bone replaced within 1-6 months from the time of the original operation. Two patients required reoperation due to bone resorption. At outpatient follow-up visits, all had scores of 3 or 4 on the Kings Outcome Scale for Childhood Head Injury. Each patient was awake, interactive, and could sit, as well as either crawl or walk with assistance. All had persistent, improving right-sided hemiparesis and spasticity. CONCLUSIONS Despite poor initial examination results, infants with severe traumatic brain injury can safely undergo decompressive craniectomy with reasonable neurological recovery. Postoperative complications must be anticipated and treated appropriately. Due to the high rate of CSF fistulas encountered in this study, it appears reasonable to recommend both the suturing in of a dural augmentation graft and the placement of either a subdural drain or a ventriculostomy catheter to relieve pressure on the healing surgical incision. Also, one might want to consider using a T-shaped incision as opposed to the traditional reverse question mark-shaped incision because wound healing may be compromised due to the potential interruption of the circulation to the posterior and inferior limb with this latter incision.

Alterations in cat cerebrocortical capillary morphometrical parameters following K+-induced cerebrocortical swelling

SummaryHistochemical, electron microscopic, and morphometrical techniques were employed in the determination of the effects attributed to K+-induced cerebrocortical swelling on cat cerebrocortical capillary diameter, length, surface area, volume, and minimal intercapillary distance.Bilaterally exposed and intact temporoparietal cerebral cortices of 4 conditioned adult cats were simultaneously superfused with isotonic, artificial CSF containing 3.5 mM K+ (control) and 54 mM K+ (experimental) for 1 h at 37°C with monitoring of systemic vital function, hematocrit, arterial blood gases, and determination of cerebrocortical tissue water content.The mean values for cerebrocapillary diameter were 5% (P<0.05) greater in swollen tissues when compared with comparable mean values determined for controls. The values for minimal intercapillary distance determined from control and experimental animals plotted as relative frequency histograms represented two distinct populations (P<0.0005). The significance of altered capillary morphometric parameters are discussed in relation to K+-induced cerebrocortical swelling.

Cerebellar Astrocytoma Manifesting as Isolated, Comitant Esotropia in Childhood

PURPOSE We encountered a 4 1/2-year-old girl with gradual onset of intermittent, comitant esotropia in the absence of diplopia and other neurologic findings. METHODS Because of the patients relatively advanced age and lack of response to hyperopic correction for accommodative esotropia, computed tomography of the head was performed. RESULTS A large cerebellar astrocytoma was identified and successfully resected. After strabismus surgery, fusion was reestablished. CONCLUSIONS The onset of comitant esotropia in an older child may indicate an underlying neurologic disorder.

Onyx embolization of a thoracolumbar perimedullary spinal arteriovenous fistula in an infant presenting with subarachnoid and intraventricular hemorrhage

Identifying a source of spontaneous subarachnoid hemorrhage (SAH) or intraventricular hemorrhage (IVH) in patients with negative results on cranial angiographic imaging can be a diagnostic challenge. The authors present the case of a 14-month-old girl who presented with lethargy and spontaneous SAH and IVH, and later became acutely paraplegic. Except for the SAH and IVH, findings on neuroimages of the brain were normal. Magnetic resonance imaging revealed an intramedullary thoracolumbar spinal cord hemorrhage that was found to be associated with arterialized veins intraoperatively. Catheter-based diagnostic angiography identified a spinal perimedullary macroarteriovenous fistula (macro-AVF) that was completely embolized with Onyx, negating the need for further surgical intervention. The authors believe this to be the first reported case of a thoracolumbar perimedullary macro-AVF presenting with SAH and IVH. In addition, descriptions of Onyx embolization of a spinal AVF in the literature are rare, especially in pediatric patients.